The poisonous constituent of the bark of Robinia pseudacacia / by Frederick B. Power.

  • Power, Frederick B. (Frederick Belding), 1853-1927.
Date:
[1913]
Catalogue details

Licence: In copyright

Credit: The poisonous constituent of the bark of Robinia pseudacacia / by Frederick B. Power. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    August, 1913. j Bark of Robinia Pseudacacia. 343 robin which was prepared in 1904, and had thus been kept, in well- stoppered bottles, for a period of nine years. This material was both in the form of dark brown scales, as originally obtained on drying the precipitated protein, and in the form of a lighter-colored powder, which was produced at the same time by triturating the first mentioned product. These two forms of the preparation were separately tested, both with amygdalin and with a well-crystallized Specimen of sinigrin (potassium myronate) in the following man- ner: Into a small test-tube, provided with a well-fitting cork, was brought a small quantity of the respective glucoside, together with some of the dry protein, and a little water subsequently added. The tubes being then corked, and the mixtures vigorously shaken, they were set aside at the ordinary temperature (16-180 C.) and occa- sionally agitated. After a period of about 24 hours or less the tubes were opened, when in the one case there was a strong odor of bitter almond oil, and in the other an equally distinctive, sharp odor of mustard oil. The unmistakable results of these tests, which are doubtless obtained much more quickly with the fresh Robinia protein, thus not only confirmed my previous observations, but they have now also been confirmed independently by five chemists in these laboratories. It was not deemed necessary to again repeat the test with milk, the coagulation of which by the protein, or an enz\ me therein contained, I had previously fully and accurately described. The properties which the protein material designated as “ robin ” has been shown to possess renders it probable that, like other similar pioducts, it is a mixture of substances, but no method is known to the present author by means of which a separation of its constit- uents could be effected without a corresponding loss of activity. It is also not known whether the toxic action of the protein is due to a substance which at the same time possesses enzymic proper- ties, but as the last-mentioned properties are so varied in character, no doubt can be entertained respecting the presence of several enzymes. Apart from the frequently observed occurrence of en- zymes, or mixtures of such, which effect the hydrolysis of amygda- in’ !t has been ascertained by Th. Bokorny (Chein. Zeitung., '1900, 24, 770 that myrosin or a similar ferment is also widely distrib- uted, having been found in plants of many different families besides he CruCl er(e, although the glucoside (sinigrin) which yields mus- tard oil has as yet only been found in the last-mentioned familv